Some types of prior art integrated circuit inductors have coils that lie in a plane that is parallel to the plane of an underlying substrate. The axis of the coils in these “in plane” inductors is perpendicular to the plane of the underlying substrate. This arrangement causes most of the magnetic flux of the inductor to penetrate into the substrate. Magnetic flux in the substrate induces lossy eddy currents and degrades the quality factor (Q) of the inductor.
To solve this problem various types of prior art “out of plane” integrated circuit inductors have been developed. One type of prior art “out of plane” inductor comprises three dimensional micro-coils that are fabricated on a planar substrate. The three dimensional micro-coils are micro-machined using micro-electromechanical systems (MEMS) technology. The micro-coils form an “out of plane” solenoid that has its longitudinal axis parallel to the surface of an underlying substrate. This arrangement causes less magnetic flux to enter the substrate and cause fewer eddy currents.
Other types of out of plane inductors have been designed in which the elements that make up the coils of the inductor are fabricated within the layers of an integrated circuit. The elements are connected to form a three dimensional out of plane coil within the integrated circuit.
The prior art methods for forming these types of out of plane inductors have significant drawbacks. The prior art methods tend to be relatively expensive, require numerous and complex manufacturing steps, and have questionable controllability. In addition, some of the prior art manufacturing methods require considerable time to perform.
Therefore, there is a need in the art for an improved system and method for manufacturing an out of plane integrated circuit inductor. There is a need in the art for an inexpensive, simple, and reliable system and method for manufacturing an out of plane integrated circuit inductor.